Aim: To study the outcome of a cohort of patients with atlantoaxial instability (AAI) treated with a combination of C1-C2 transarticular screws and C1 lateral mass fixation. Background: Several surgical techniques have been described for stabilization of the atlantoaxial complex. Each technique differs in its biomechanical properties, advantages, and disadvantages. In this series, we describe our experience with a combined four-point fixation technique that combines C1-C2 transarticular screws with C1 lateral mass fixation for AAI. Materials and methods: We present a single-center retrospective case series of 30 patients who were surgically treated for AAI over one decade. All patients presented with symptoms and signs of AAI and consequently underwent extensive clinical and radiological evaluation prior to surgery. The median follow-up of our cohort was 8.3 months (3–143) with three patients lost to follow-up. Pre and postoperative symptoms were compared, including the visual analog scale (VAS) scores for neck and C2 radicular pain. All patients’ preand postoperative lateral dynamic cervical radiographs were evaluated and the posterior atlantodental interval (PADI) was measured. Ranawat functional disability score was used for pre and postoperative evaluation. Results: Of the 30 patients, 8 were male and 22 female. The mean age was 60.4 years (18-78 years). The median hospital stay following surgery was 5 days (2–25 days). The mean preoperative VAS score for neck pain was 6.3 vs 4.3 at the first postoperative review (p ≤ 0.001) on paired comparison. Ranawat scores were available for 26 out of 30 patients. The scores improved following surgery in 8/26 (30.7%) patients, did not change in 17 (65.4%) patients, and deteriorated in only one patient (3.8%). Like the VAS score, improvement in Ranawat score following surgery was significant (p = 0.02). ORIGINAL ARTICLE 1,4,6,7Consultant, 2,3Neurosurgery Registrar, 5Neuroradiology Registrar 1-5,7Department of Neurosurgery, John Radcliffe Hospital Oxford, UK 6Academic Neurosurgery Unit, St George’s, University of London London, UK Corresponding Author: Murtuza Sikander, Consultant Department of Neurosurgery, John Radcliffe Hospital, Oxford UK, Phone: +441865234860, e-mail: murtuza.sikander@ouh. nhs.uk 10.5005/jp-j urnals-10039-1105 Complications in this series included two unilateral intraoperative vertebral artery injuries associated with placement of C1-C2 transarticular screws, another patient had worsening C2 pain following surgery, and three patients had numbness in the C2 distribution following the procedure. Radiologically, two patients had suboptimal unilateral C2 screw placement despite satisfactory intraoperative fluoroscopic imaging. There were no infections and no implant failure. Conclusion: The addition of C1 lateral mass screws to C1-C2 transarticular screw fixation for the treatment of AAI is an effective and safe procedure worthy of note. Our results and experience prove that this method is extremely beneficial where decompression of the posterior elements of C1 is required and may obviate the need of additional posterior wiring traditionally described. Further studies are necessary to look at the longterm fusion rates and compare them with other procedures.

Objectives: Anterior cervical discectomy and fusion (ACDF) is a common operative treatment of compressive pathology of the cervical spinal cord, when caused by one or more degenerated intervertebral discs or related osteophytes. In addition to intra-operative radiographs to confirm spinal level before discectomy and implant position after insertion, traditional practice is to obtain post-operative antero-posterior and lateral plain radiographs (XR) before hospital discharge, despite a paucity of evidence supporting their benefit to patient care. Minimising unnecessary radiation to radiosensitive neck structures is desirable, and furthermore, with increasing financial pressure on healthcare resources, routine investigations should be clinically justified and evidence-based. We aim to compare the utility of routine post-operative cervical spine X-rays following ACDF.Methods: We compare two groups of consecutive patients undergoing ACDF in a single UK neurosurgical centre. The first group (n = 1 09) received routine post-operative XR imaging, and the second group (n = 113) received radiographs only when clinically indicated.Results: There were no differences in post-operative complication rates (4.6% vs. 5.3%), or requirement for further imaging or of further operative intervention (1.8% vs. 0.9%). The group that did not have routine post-operative radiographs had a significantly shorter stay in hospital (median two days vs. three days). There were no patients in either group where post-operative XR changed clinical management and mandated revision surgery or further imaging. All cases requiring surgery or further imaging were identified by clinical deterioration.Conclusions: We suggest that the practice of obtaining routine radiographs of the cervical spine following ACDF should be abandoned, unless there is a clear clinical indication.

Figure 1. A: Preopera tive lateralcervical spine x-ray shows the massive anterior osteophytes at C2 and C3 and ossification of the anterior longitudinal ligament at caudal levels. B: Preoperative MRI confirms extensiveossifica tionoftheanteriorlongitudinalligamentacrossmultiplecontiguousvertebraewithrelative preservation of the intervertebral disc height and /JO evidenceof degenerative or ankylosing spine disease. Thesefindingsfulfill the criteria for a diagnosis of DISH. The spinal CIl nal is /JOt affected. A 72-year-old man B was referred to the Department of Neurosurgery at the John Radcliffe Hospital for surg ical managem ent of dysphagia, the underlying cause of which had eluded diagno sis for almost 10 years. At his initial presentation nearly a decade earlier, he had reported symptoms of high dysph agia for solid foods and episodes of coughing and chokin g during meals. Findings on the physical examination at that tim e were normal, and a barium swallow test detected no obvious abnormality. A provi sional diagnosis of mild neuromuscular incoo rdination of the pharynx was made. Over a number of years, the patient's symptoms pro gressed. A videofluoroscopic swallow examination demonstrated a delayed and incon sistent cough reflex, evidence of silent aspiratio n, and pooling of secretio ns in the valleculae and piriform sinuses. In the cervical spine, an x-ray showed large anterior osteophytes at C2 and C3 (figure 1, A). These osteophytes were fou nd to int errupt bolus flow and impe de the action of ph aryngeal constrictors. Magnetic resonance imaging (MRI) (figure 1, B) and computed tom ography of the cervical spine confirmed an underlying diagno sis of diffuse idiop ath ic skeletal hyperostosis (DISH) . Surg ical excision of the osteophytes was achieved via an anterior cervical approach. At the 3-mo nth followup, the patient repo rted a significant reduction of his dysph agia. Postoperative cervical xrays confirmed that a satisfactory decompression of th e ph arynx had been accomplished (figure 2). Also known as Forestier disease, DISH is estima ted to affect about 10% of th e popul ation. I It is more common in men, and its prevalence increases with age (35% in men olde r than 70 years); it is also more severe in men.' In some cases DISH is asymptomatic, and the